The board says there were 10,182 sales through the Multiple Listing Service last month, up 3.4 per cent from 10,544 in the same month last year.
However, the board says the average selling price last month was $542,174, up by 5.4 per cent compared with $514,567 in May 2012.
The board attributed the higher average price to a tight market for single-detached and semi-detached home sales in Toronto.
Average condominium apartment prices were also up slightly.
Toronto Real Estate Board president Ann Hannah says a number of households who put their decision to buy on hold last year as a result of stricter lending guidelines are starting to become active again.